Sec Form 4 Filing - NEIDORFF MICHAEL F @ CENTENE CORP - 2012-02-29

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person NEIDORFF MICHAEL F 2. Issuer Name and Ticker or Trading Symbol CENTENE CORP [ CNC] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director _____ 10% Owner X __ Officer (give title below) _____ Other (specify below) Chairman, President and CEO (Last) (First) (Middle) 7700 FORYSTH BOULEVARD 3. Date of Earliest Transaction (MM/DD/YY) 02/29/2012 (Street) ST. LOUIS, MO63105 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 02/29/2012 M 100,000 A $ 13.58 1,782,891 ( 1 ) D Common Stock 02/29/2012 S 100,000 ( 2 ) D $ 48.97 1,682,891 ( 1 ) D Common Stock 03/01/2012 M 22,759 A $ 13.58 1,705,650 ( 1 ) D Common Stock 03/01/2012 M 45,832 A $ 13.98 1,751,482 ( 1 ) D Common Stock 03/01/2012 S 68,591 ( 2 ) D $ 48.93 1,682,891 ( 1 ) D Common Stock 03/02/2012 M 81,409 A $ 13.98 1,764,300 ( 1 ) D Common Stock 03/02/2012 S 81,409 ( 2 ) D $ 47.45 1,682,891 ( 1 ) D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares Common Stock Option (right to buy) $ 13.58 02/29/2012 M 100,000 08/26/2008 08/26/2013 Common Stock 100,000 $ 13.58 22,759 D Common Stock Option (right to buy) $ 13.58 03/01/2012 M 22,759 08/26/2008 08/26/2013 Common Stock 22,759 $ 13.58 0 D Common Stock Option (right to buy) $ 13.98 03/01/2012 M 45,832 12/16/2004 12/16/2013 Common Stock 45,832 $ 13.98 154,168 D Common Stock Option (right to buy) $ 13.98 03/02/2012 M 81,409 12/16/2005 12/16/2013 Common Stock 81,409 $ 13.98 72,759 D Phantom Stock $ 0 ( 3 ) 02/11/2011 02/11/2011( 4 ) Common Stock 50,569.001 50,569.001 D Common Stock Option (right to buy) $ 17.85 07/27/2007 07/27/2014 Common Stock 180,000 180,000 D Common Stock Option (right to buy) $ 25.4 12/13/2008 12/13/2015 Common Stock 200,000 200,000 D Common Stock Option (right to buy) $ 25.21 12/12/2009 12/12/2016 Common Stock 96,034 96,034 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other NEIDORFF MICHAEL F 7700 FORYSTH BOULEVARD ST. LOUIS, MO63105 X Chairman, President and CEO Signatures /s/ William N. Scheffel (executed by attorney-in-fact) 03/02/2012 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Ownership includes 540,000 shares of restricted stock subject to vesting requirements. ( 2 )This sale is pursuant to a 10b5-1 Trading Plan established on February 15, 2012 and for diversification of assets for estate planning. The weighted average price for this transaction is reported within the form. Full information regarding the number of shares at each price is available upon request. ( 3 )Each share of phantom stock represents the right to receive the fair market value of one share of Centene common stock. ( 4 )The phantom stock has no formal expiration date. The phantom stock will be settled in cash or other non-Company securities upon Mr. Neidorff's termination with the Company or on such other date Mr. Neidorff may elect.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

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